The invention relates to a fuel delivery unit which is provided for arrangement in a fuel tank of a motor vehicle, having a surge chamber for collecting fuel and having a delivery pump for delivering fuel from the surge chamber to an internal combustion engine of the motor vehicle.
Fuel delivery systems of this type are frequently used in modern motor vehicles and are known from practice. The surge chamber is generally arranged at a location in the fuel tank in which it is preferably filled during a first filling of the tank. The surge chamber is therefore also filled.
A disadvantage of the known fuel delivery units is, however, that, when the surge chamber is virtually empty, air can be sucked in by the delivery pump and can accumulate in the lines leading to the internal combustion engine. When reserve fuel is fed in thereafter, the air situated in the lines prevents fuel from being able to be delivered to the internal combustion engine. Furthermore, the delivery pump may be damaged if it runs dry.
The invention is based on the object of designing a fuel delivery unit of the type mentioned at the beginning in such a manner that it reliably prevents air from passing into the lines leading to the internal combustion engine.